A device for applying glue to a cut surface on the leading end of each moving wood veneer sheet for subsequently jointing such end with a similarly-cut trailing end of preceding veneer sheet is disclosed by Publication of Examined Japanese Patent Application No. 62-16801 (1987). This device includes a conveyer for feeding veneer sheets successively, an intermittently rotatable endless belt provided midway of the feed conveyer and extending perpendicularly with respect to the direction of veneer feeding with the outer surface of its upper run positioned substantially level with the plane in which the veneer sheets are advanced by the conveyer, and a glue supply located adjacent the upstream end of the upper run of the above intermittently movable belt for depositing glue onto said belt while it is being moved so that either a continuous line or a series of individual spots of glue may be formed on the outer surface of the upper run of the belt. Application or coating of glue to the cut end in this device is accomplished by feeding the veneer sheet with its leading end moved against the glue deposit extending in parallel relation to the line defined by the end, thus the glue being picked up by and attached to the leading end. The device according to the above Publication is adapted to use for jointing veneer sheets in side-to-side relation to each other, or jointing the sheets along a line parallel to the fiber orientation of wood veneer sheet, and, therefore, each veneer sheet is moved by the conveyer with its fiber orientation directed in transverse relation to the direction in which the sheet is moved.
With such a device, however, satisfactory uniformity in the glue application can be accomplished only if the leading end of the veneer sheet is maintained straight at least when that end is moved past the glue deposit on the belt to pick up the glue by scooping. To be more specific, moving a veneer sheet having a waved leading end against the glue deposit on a flat surface will result in poor partial application of the glue to the end.
In view of the characteristic of veneer sheet produced, e.g., by peeling that it tends to be curled or so bent that its longitudinal ends become wavy, the above device is unable to apply glue uniformly over the cut surface on such longitudinal ends. Additionally, since the strength of a wood veneer sheet is generally much lower in the direction along its fiber orientation than it is in the direction thereacross, poor glue application will, as would be understood by those skilled in the art, affect the overall strength of a veneer sheet having therein a joint specifically formed by the longitudinal ends of two veneer sheets.